Conventionally, as a coating method by electrodeposition of polyimide, a method is known which includes dissolving polyamic acid, which is a polyimide precursor, in an organic polar solvent, adding a poor solvent and water, performing electrodeposition using the obtained aqueous dispersion type solution for electrodeposition, and heating the electrodeposited film at 240-260° C. to give an imide film (patent documents 1-3). Aqueous polyamic acid dispersion for electrodeposition has poor preservation stability since polyamidic acid is easily decomposed, and moreover, the electrodeposited coating film requires a high temperature treatment for imidation. In addition, As described in patent document 4, there is a method capable of electrodeposition by introducing carboxylic acid into polyimide wherein polyamic acid is directly imidated. However, the method is not entirely satisfactory in terms of resistance to the development of peeling and cracks in the electrodeposited film. In addition, an electrodeposition coating composition containing solvent-soluble polyimide and a hydrophilic polymer in the same particle is described in patent document 5, and use of diamino organosiloxane as a diamine component is also described. However, the resistance to the development of peeling and cracks in the electrodeposited film is not satisfactory. Furthermore, patent document 6 describes a polyimide silicone type resin composition. However, the composition is not an electrodeposition composition and is associated with problems of the above-mentioned instability and the need of a high temperature treatment due to the use of polyamic acid. Therefore, the Applicants have already proposed an electrodeposition coating composition having superior heat resistance, which is capable of solving such problems in the prior art and forming, on a body to be electrodeposited, a highly reliable high-insulation electrodeposited film that resists development of peeling and cracks and an electrodeposition method using the composition (patent document 7). However, since the electrodeposition coating composition consists of a mixture of several kinds of solvents, it is defective in that the behavior as an electrodeposition coating greatly varies depending on a slight change in the mixing ratio of the solvents, restriction of the use environment such as temperature, vapor amount and the like is severe, and the film property after electrodeposition coating tends to be nonuniform. In addition, its slow electrodeposition speed causes low electrodeposition efficiency, and an electrodeposited film having a sufficiently large thickness cannot be afforded.    patent document 1: JP-A-49-52252    patent document 2: JP-A-52-32943    patent document 3: JP-A-63-111199    patent document 4: JP-A-9-104839    patent document 5: JP-A-2000-178481    patent document 6: JP-A-2003-213129    patent document 7: JP-A-2005-162954    patent document 8: WO99/19771    patent document 9: U.S. Pat. No. 5,502,143